Electric bell for alarm clocks

ABSTRACT

An electric bell for attachment as a unit to an electric alarm clock, the unit including a printed circuit board having a transistorized oscillator circuit on one side thereof and a leaf spring oscillating hammer on the other side thereof, the hammer being generally enclosed by a bell.

[451 Mar. 12, 1974 United States Patent [191 Flaig et al.

[56] References Cited UNITED STATES PATENTS ELECTRIC BELL FOR ALARM CLOCKS Inventors: Hans Flaig, Schr'amberg-Sulgen;

26 2 99 9 3323 //0/ 00 0 44/4 3303 .4. u 3 H mkm m a nWu a o GFHP 59 7766 9999 1111 ///l 5 35 1 5003 2804 7825 7 74 3333 [73] Assignee:

Primary Examiner.lohn W. Caldwell Assistant Examiner-William M. Wannisky Attorney, Agent, or Firm-Burns, Doane, Swecker & Mathis 22 Filed:

[57] ABSTRACT An electric bell for attachment as a unit to an electric Foreign Application Priority Data June 8, 1970 Germany;...........:.

alarm clock, the unit including a printed circuit board havinga transistorized oscillator circuit on one side thereof and a leaf spring oscillating hammer on the other side thereof, the hammer being generally enclosed by a bell.

12 Claims, 6 Drawing Figures 0 9 0 2 0 l 13 s a 00-0 28 580 2 m 0 n97 4 11 1 m ,3 3 molm v 11 6 3H U W M 9 PAIENTED m 1 2 I974 SHEET 1 0F 2 IN V EN TORSI 6 44 5 [24/6 P r m numz 1914 3Q797l013 sum 2 [1F 2 ELECTRIC BELL FOR ALARM CLOCKS BACKGROUND OF THE INVENTION The invention relates to an electric bell for alarm clocks, especially for battery fed clocks, with a hammer carrying leaf spring oscillator and a permanent magnet arrangement which acts upon the coil arrangement of a transistorized drive circuit.

An electric bell of the above-mentioned type built into the clockwork mechanism has been known, whereby the leaf spring oscillator at the time of alarm is struck by a special spring loaded lever arrangement.

The object of the invention is the creation of an electric bell of the above-mentioned type which operates without contact and which can be added as an independent construction unit to a clockwork mechanism. According to the invention, this is achieved through the arrangement as one constructional unit on a common base plate, the leaf spring oscillator, the bell, the electric construction elements and the connecting conductors. A plate made of an insulating material is preferably used as a base plate and is laminated or coated with an electrically conductive material. Alternatively, the base plate may consist of lamination compressed material.

The electrically conductive lamination provided on the base plate is developed in a known manner into conductive paths to connect the electric construction elements. At least one of the conductive paths of the base plate that is to be connected with the source of the voltage is positioned for practical purposes into the area of the place of attachment of the base plate to be connected with the voltage source. In this manner, an electric connection with the source of the feed voltage is established automatically during the mounting of the base plate. Whenever only one of the points of attachment is connected with a pole of the voltage source, the conductor path that is to be connected with the second pole of the voltage source can be guided into the area ofa recess in the base plate, which has been developed for the introduction of an AMP plug.

Preferably, the plane of oscillation of the leaf spring oscillator is parallel to the base plate. At the same time, the coil arrangement may adjoin the permanent magnet and may be inserted in a recess of the base plate, which has been arranged preferably on the side of the base plate facing away from the oscillator. The side of the base plate, lamination coated with an electrically conducting material, effectively faces away from the leaf spring oscillator. v

The leaf spring oscillator may be provided with angular lobes in the area'of its place of attachment, which lobes engage in recesses in the base plate as assurance against twisting.

The permanent magnet arrangement provided on the leaf spring oscillator effectively contains at least one rectangular block magnet acting upon one side of the coil arrangement. Preferably, however, two rectangular block magnets have been provided acting in the opposite sense on the sides of the coils. It will be advantageous if the leaf spring consists of magnetically conductive material and serves as a partial return for the permanent magnet arrangement.

The permanent magnet arrangement can be attached to at least one angular lobe of the leaf spring oscillator. In the case of use of two permanent magnets lying one beside the other in one plane, two oppositely angular lobes of the leaf spring can be provided, each of the lobes covering up one half of the area of a magnet.

Preferably, the coil arrangement is covered by a return plate on the side thereof which faces away from the permanent magnet arrangement. In the case of the use of one permanent magnet, the return plate preferably reaches into the area of the place-of attachment of the leaf spring to establish, in this manner, a magnetic return via the leaf spring oscillator. The return plate may be connected with the support for the bell by a common means of attachment.

In a power line going to the base plate, a switch operated by the clockwork mechanism can be provided which is closed at the time of the alarm. It is also possible to guide a conductor path of the base plate into the area of a contact spring controlled by the clockwork mechanism. At the same time, the conductor path comes into contact with the contact spring and can be connected into the base-emitter circuit of the transistor.

These and other objects and advantages will be readily apparent from the claims and from the following detailed description when read in conjunction with the drawings. The invention will be explained in more detail on the basis of the drawings and embodiments given by way of example.

THE DRAWINGS FIG. 1 shows a perspective view of the bell according to the invention in a condition ready to be attached to an alarm clock;

FIG. 2 is an exploded pictorial view of the bell of FIG. 1;

FIG. 3 is a side view of the bell of FIG. 1;

FIG. 4 is a section in elevation along the lines IV-IV of FIG. 3;

FIG. 5 is a modification of the permanent magnet arrangement attached to the leaf spring oscillator; and,

FIG. 6 is a schematic circuit diagram of the transistor circuit of the bell of the present invention.

THE DETAILED DESCRIPTION In FIGS. 1 4, the numeral 10 designates the base plate which, for example, consists of a lamination compressed material and which, on its underside, has been coated with an electrically conductive material such as copper. This coating has been developed in a known manner in individual conductor paths, so that they establish the connection between individual electric switch elements 24 27. These electric switch elements, as later explained, are also attached to the base plate 10.

The conductive paths to be connected with the voltage source, for example, to a dry cell battery, may be guided into the area of the two places of attachment, for example, into the area of two attaching holes 10a 10c,-so that the mounting of the base plate 10 simultaneously establishes the electric connection leading to the voltage source. In the present case, one of the conductive paths has been guided into the area of the attaching hole 10b, while the second conductive path that is to be connected with the source of voltage has been guided into the area of a slit 10d in the base plate 10. An AMP plug, connected with the second pole of the source of voltage via a strand, can be inserted in this slit. A switch 28 has been provided between the AMP plug and the battery pole which is controlled by the clockwork mechanism, so that at the time of the alarm, the switch is closed and the electric circuit begins to operate.

For example, the switch 28 can be located in the feed line leading to the positive pole of the voltage source, as shown in FIG. 6. It is also possible to make the switch directly by means of a spring which fits against a conductive path of the base plate and which is controlled by the clockwork mechanism, so that the spring normally is lifted off the conductor path but presses against the above-mentioned conductor path at the time of alarm. It is naturally also possible to provide a conductor path with a place of interruption which is bridged by a spring controlled by the clockwork mechanism. Such a switch 28a can be provided, for example, as shown in FIG. 6.

With continued reference to FIG. 1, a leaf spring 14 is bent at one end 140 to form a foot with bent over lobes 14d. These bent lobes 14d engage with corresponding recesses of the base plate and they will prevent a twisting of the leaf spring 14 on the base plate. The attachment of the leaf spring may be accomplished with the aid of a screw 29.

The leaf spring 14 at its free end carries a hammer 15 to strike against a bent element 11a of a bell 11. The leaf spring 14 has furthermore been provided with bent lobes 14a and 14b, to which oppositely magnetized, permanent rectangular block magnets 16 and 17 are attached. Preferably, the leaf spring 14 consists of a magnetically conductive material so that the lobes 14a and 14b represent partial returns for the magnets 16 and 17.

At its underside, as best seen in FIGS. 3 and 4, the base plate 10 has been provided with a recess 18 in which a coil arrangement comprising a control coil and a driving coil 19 has been inserted. The coil arrangement 19, 20 may be attached with the aid of a return plate 21, which has been attached jointly to a belfry 12 carrying the bell 11 with the help of bolts 22 and nuts 23.

A window 13 may be provided in the base plate 10 through which hammer 15 can be observed.

The numerals 24 to 27 designate the electric switch elements which are used in the circuit shown in FIG. 6. The attaching wires of the switch elements are guided effectively through holes in the base plate and are connected below the base plate 10 with a conductive layer in a manner well known in the art.

In the case of the modified embodiment, according to FIG. 5 given by way of example, a leaf spring 34 has been provided with a hammer 35. The leaf spring 34 has been bent at 34b and has been attached to the base plate 10 with the aid of a screw 39. An individual permanent magnet 36 may be held by a bent lobe 34a of the leaf spring 34. The two coils 19, 20 are inserted below the base plate 10 into the recess 18. A return element 31 reaches below one side of the coil arrangement 19, 20 and leads into the area of the place of attachment of the leaf spring 34. The leaf spring 34 in this case has likewise been produced of electrically conductive material so that a return will lead from magnet 36 via the bent lobes 34a, the leaf spring 34 and its point of attachment,as well as via the return element 31 to one side of the coil arrangement 19, 20.

FIG. 6 shows schematically the construction of the transistor circuit for the drive of the leaf spring oscillator. We are dealing in this case with a self-starting circuit as known per se. A switch 28 may be operated by the clockwork mechanism to establish a connection with the positive pole of a battery. Instead of switch 28, there may also be a switch 28a provided which lies in the emitter-base circuit of the transistor 24. In this place, only very small currents are to be switched.

ADVANTAGES AND SCOPE OF THE INVENTION The bell according to the invention is very simple in its structure and can be added to a clockwork mechanism as a unit. At the same time, the bell operates very reliably since the drive of the leaf spring oscillator is accomplished via a contactless path. The printed circuit board base plate carries all of the electrical circuit components, as well as the mechanical elements such as the bell and hammer. Power may be derived solely from the power of the alarm clock, resulting in a smaller and lighter physical package.

The present invention may thus be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by theforegoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed is:

1. An electric bell for an alarm clock comprising:

a base plate recessedon one side thereof;

an electric circuit means including a transistor and a coil carried in the recess by said base plate;

a magnetically conductive leaf spring oscillator member carried by said base plate in the side opposite to the recess, said oscillator member including a hammer and a permanent magnet carried by said hammer in operable relationship to said coil and further including means to prevent the twisting thereof; and, v a bell carried by said base plate in overlying relationship to said leaf spring oscillator member, said bell including means for connecting the electric bell to an alarm clock and simultaneously connecting said base plate to a source of power, a plate of magnetic material carried by said base plate on the opposite side of said coil from said base plate, abelfry car-v ried by said base plate, said belfry being secured to said base plate and said magnetic plate being secured to said base plate by the same means, and a contact responsive to said alarm clock for contacting said base plate in the base-emitter circuit of said transistor.

2. An electric bell for an alarm clock comprising:

a base plate;

an electric circuit means including a transistor and a coil carried by said base plate;

a leaf spring oscillator member carried by said base plate, said oscillator member including a hammer, a first permanent magnet carried by said hammer on one side of said leaf spring and a second magnet of opposite polarity carried on the other side of said leaf spring in operable relationship to said coil; and, I

a bell carried by said base plate in overlying relationship to said leaf spring oscillator member.

3. The electric bell of claim 2 wherein said base plate comprises an insulating material having an electrically conductive surface.

4. The electric bell of claim 2 including means for connecting the electric bell to an alarm clock and simultaneously connecting said base plate to a source of power.

5. The electric bell of claim 2 wherein the plane of oscillation of said leaf spring oscillator is parallel to said base plate.

6. The electric bell of claim 2 wherein said base plate is recessed from the side thereof opposite to said oscillator; and,

wherein said coil is mounted in said recess.

7. The electric bell of claim 2 wherein said leaf spring oscillator includes means to prevent the twisting thereof.

8. The electric bell of claim 2 wherein said leaf spring is magnetically conductive and is included in the magnetic circuit of said permanent magnet.

9. The electric bell of claim 2 including a plate of magnetic material carried by said base plate on the opposite side of said coil from said base plate.

10. The electric bell of claim 9 including a belfry carried by said base plate, said belfry being secured to said base plate and said magnetic plate being secured to said base plate by the same means.

11. The electric bell of claim 2 including a contact spring responsive to said alarm clock for contacting said base plate.

12. The electric bell of claim 11 wherein said contact spring contacts said base plate in the base-emitter circuit of said transistor. 

1. An electric bell for an alarm clock comprising: a base plate recessed on one side thereof; an electric circuit means including a transistor and a coil carried in the recess by said base plate; a magnetically conductive leaf spring oscillator member carried by said base plate in the side opposite to the recess, said oscillator member including a hammer and a permanent magnet carried by said hammer in operable relationship to said coil and further including means to prevent the twisting thereof; and, a bell carried by said base plate in overlying relationship to said leaf spring oscillator member, said bell including means for connecting the electric bell to an alarm clock and simultaneously connecting said base plate to a source of power, a plate of magnetic material carried by said base plate on the opposite side of said coil from said base plate, a belfry carried by said base plate, said belfry being secured to said base plate and said magnetic plate being secured to said base plate by the same means, and a contact responsive to said alarm clock for contacting said base plate in the base-emitter circuit of said transistor.
 2. An electric bell for an alarm clock comprising: a base plate; an electric circuit means including a transistor and a coil carried by said base plate; a leaf spring oscillator member carried by said base plate, said oscillator member including a hammer, a first permanent magnet carried by said hammer on one side of said leaf spring and a second magnet of opposite polarity carried on the other side of said leaf spring in operable relationship to said coil; and, a bell carried by said base plate in overlying relationship to said leaf spring oscillator member.
 3. The electric bell of claim 2 wherein said base plate comprises an insulating material having an electrically conductive surface.
 4. The electric bell of claim 2 including means for connecting the electric bell to an alarm clock and simultaneously connecting said base plate to a source of power.
 5. The electric bell of claim 2 wherein the plane of oscillation of said leaf spring oscillator is parallel to said base plate.
 6. The electric bell of claim 2 wherein said base plate is recessed from the side thereof opposite to said oscillator; and, wherein said coil is mounted in said recess.
 7. The electric bell of claim 2 wherein said leaf spring oscillator includes means to prevent the twisting thereof.
 8. The electric bell of claim 2 wherein said leaf spring is magnetically conductive and is included in the magnetic circuit of said permanent magnet.
 9. The electric bell of claim 2 including a plate of magnetic material carried by said base plate on the opposite side of said coil from said base plate.
 10. The electric bell of claim 9 including a belfry carried by said base plate, said belfry being secured to said base plate and said magnetic plate being secured to said base plate by the same means.
 11. The electric bell of claim 2 including a contact spring responsive to said alarm clock for contacting said base plate.
 12. The electric bell of claim 11 wherein said contact spring contacts said base plate in the base-emitter circuit of said transistor. 